Equipment (Modems,Gateways)
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'True Bridge Mode’ vs. 'Pass-Through Mode'

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Community Manager

'True Bridge Mode’ vs. 'Pass-Through Mode'

With bridged devices the “Public” IP is announced directly to the customer owned managed Firewall or Router versus a Private IP (10.1.10.X or 192.168.1.X, etc.).


If you want to use ‘true bridge mode’, please note the following characteristics of devices in bridge mode:

  • Does not have router capabilities or support LAN DHCP
  • Cannot have a fixed Static IP assignment


Comcast Business customers can select devices from the following equipment list that are capable of running in bridge mode: equipment options


Comcast Business customers can set their existing Comcast Business Wireless Gateways to true bridge mode by:

  1. Log into the modem
  2. Disable Private WiFi (2.4GHz and 5GHz) to stop the gateway from broadcasting WiFi Network SSIDs after it is put into True Bridge mode True%20Bridge%20Mod%20Step%202%20Cisco%20BWG.pngDisabling WiFi on Comcast Business Wireless Gateway
  3. Navigate to the Gateway – At a Glance screen in the GUI True%20Bridge%20Mode%20Cisco%20BWG%20Step%203.pngGateway - At a Glance screen in Comcast Business Wireless Gateway
  4. Click Enable to the right of Bridge Mode True%20Bridge%20Mode%20Cisco%20BWG%20Step%204.pngEnable Bridge Mode on Comcast Business Wireless Gateway
  5. Click OK                          True%20Bridge%20Mode%20Cisco%20BWG%20Step%205.pngConfirm Bridge Mode screen on Comcast Business Wireless Gateway

**Note**:  the Cisco 3939B BWG cannot support WiFi in bridge mode.




Pass-through Mode describes a modem which has its LAN DHCP and Firewall manually disabled through the user interface. This allows traffic to pass-through the modem to a routing device and can be used if the customer has a Static IP address. This is not true Bridge Mode and does not convert the gateway to a basic cable modem. This mode allows most of the routing capabilities of the gateway to remain intact.


Comcast Business customers can put their Comcast Business Wireless Gateway into pass-through mode by:

  1. Navigate to Gateway > Firewall > IPv4 for Firewall settings Firewall%20Cisco%20Step%202.pngFirewall/Smart Packet Detection on Comcast Business Wireless Gateway

As a best practice for customer with their own firewall, ensure Custom Security is selected and Disable Entire Firewall is checked.


Comcast Business customer with a SMC 8014, SMC D3G, or Netgear CG3000 Comcast Business modem can put their modem into pass-through mode by:

  1. Navigate to Firewall - Firewall Options for Firewall settings Firewall%20Non%20BWG.jpg